JPH071852Y2 - Antenna device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a conformal array antenna used in a radar system.

[Conventional technology]

FIG. 3 is a block diagram showing a conventional antenna device. In FIG. 3, (1) is a conformal array antenna having a plurality of elements provided on a hemisphere, and (2) is the conformal array antenna (1). Hemispherical structural substrate,
(3 ₁ ) to (3n) are n arranged along the structural substrate.
Number of elements, (4 ₁ ) to (4n) are n signal lines connected to the elements (3 ₁ ) to (3n), and (5) is the signal line (4 ₁ ) to
This is a microwave beam forming circuit connected to (4n). Figure 4 is a block diagram of a device (3 ₁₎ ~ (3n) which constitutes the conformal array antenna (1), is indicative for (3 ₁₎ as an example (6 ₁₎ is the element antenna .

Next, the operation will be described. Microwave power is the hemispherical structural substrate (2) of the conformal array antenna (1)
The signal lines (4 ₁ ) to (4n) received by the element antennas (6 ₁ ) to (6n) of the elements (3 ₁ ) to (3n) arranged along
The signal is transmitted to the microwave beam forming circuit (5) via the microwave beam forming circuit (5) and is combined as it is to form a beam by using a microwave phase shifter, a microwave variable attenuator, a microwave switch, a microwave combiner and the like.

[Problems to be solved by the device]

Since the conventional antenna device is configured as described above, the antenna beam can be arbitrarily formed over a half space, but many antenna components such as phase shifters, attenuators, switches, couplers, and distributors are used. In the case of constructing the beam, the shape loss becomes large and only a limited number of beams can be combined at the same time. Moreover, the shadow of the used as part of the radar apparatus is assumed that for a beam in a desired direction, when viewed conformal array antenna (1) from the desired direction element (3 ₁₎ ~ (3n) The elements in the area marked with can no longer be used effectively, and especially when the scanning angle from the zenith direction approaches 90 °, nearly half of the elements cannot be used effectively.

In addition, the aperture of the conformal array antenna (1) is set to 2
In the case of forming a monopulse pattern by using the pattern of each part, since the conventional antenna device uses the microwave beam forming circuit (5), it is possible to configure for one observation direction. However, when the observation direction changes significantly, one of the apertures becomes invisible, and the pattern of the difference cannot be formed, which is a big problem when the target is tracked using the conformal array antenna (1).

The present invention was made in order to solve the above problems, and it is possible to combine a plurality of monopulse patterns at the same time and effectively use all the elements at all times, and it is possible to track a target over a wide angle. The purpose is to obtain the device.

[Means for Solving the Problems]

The antenna device according to the present invention comprises elements (3 ₁ ) to (3n)
Add a low noise amplifier and analog digital converter to
It is equipped with a circuit that converts the outputs of elements (3 ₁ ) to (3n) into a digital signal, synthesizes a plurality of beams with a digital beam forming circuit, and forms a monopulse pattern using any two of these beams. It was done.

[Action]

In this invention, a digital beam forming circuit synthesizes a plurality of digital signals including phase amplitude information from the respective elements (3 ₁ ) to (3n) in parallel and then synthesizes a monopulse pattern using an arbitrary pattern between two lines. As a result, multiple monopulse patterns can be combined at the same time, and all elements (4) can be effectively used to form a monopulse pattern that can be used for radar target tracking over a wide space.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. First
In the figure, (1) is a conformal array antenna in which a plurality of elements are provided on a hemisphere, (2) is a hemispherical structural base constituting the conformal array antenna (1),
(3 ₁ ) to (3n) are n arranged along the structural substrate.
Number of elements, (4 ₁ ) to (4n) are n signal lines connected to the elements (3 ₁ ) to (3n), and (7) is the signal line (4 ₁ ) to
Digital beam forming circuit connected to the _{(4n), (8 1)} ~
(8m) is the digital beam forming circuit (7) m-number of output terminals, (9) the output terminal (8 ₁₎ ~ (8m) to the connected monopulse pattern forming circuit (10) is the monopulse pattern formation These are the k output terminals of the circuit (9).

Figure 2 is a block diagram of a device (3 ₁₎ ~ (3n) which constitutes a conformal array antenna (1), which shows the element (3 ₁₎ as an example (6 ₁₎ of antenna elements,
(11 ₁ ) is a low noise amplifier, and (12 ₁ ) is an analog digital converter.

Next, the operation will be described. The microwave signals received by the element antennas (6 ₁ ) to (6n) of the elements (3 ₁ ) to (3n) mounted on the structural base body (2) of the conformal array antenna (1) are low noise amplifiers ( It is amplified in 11 ₁ ) to (11n). The microwave signal amplified by the low noise amplifiers (8 ₁ ) to (8n) is directly or converted to IF, and the output is digital including the phase and amplitude information by the analog digital converters (12 ₁ ) to (12n). Converted to a signal. The digital signal is transmitted through the signal lines (4 ₁ ) to (4n), and the digital beam forming circuit (7) uses a technique such as individual Fourier transform, fast Fourier transform, or Winograd Fourier transform, not as a microwave signal but as a digital signal. Beam-combined. digital signal monopulse pattern is calculated sum and difference of each signal every arbitrary two in monopulse pattern forming circuit (9) via an output terminal (8 ₁₎ ~ (8n) corresponding to m of beams To form
Output from the monopulse pattern output terminals (10 ₁ ) to (10k). Therefore, it is possible to form a monopulse pattern at the same time over a half space, and at the same time, it is possible to perform multi-target tracking.

In the above embodiment, a hemisphere is used as the conformal array antenna (1), but the invention is not limited to this. The outside and the cylinder of structures such as ships, aircraft, missiles, land vehicles, satellites, ground radar sites, etc. It may have a shape having a part of a spherical cone or the like or a part of a curved surface having a combination thereof or a plurality of points.

Regarding polarized waves, circular polarized waves can be used without being limited to linear polarized waves.

[Effect of device]

As described above, according to the present invention, the microwave signal of the conformal array antenna (1) is converted into a digital signal and combined by the digital beam forming circuit (7) and the monopulse pattern forming circuit (9). All monopulse pattern forming elements (3 ₁ ) possessed by
Problems related to the effective use of (3n) are improved, and performance is greatly improved in terms of multi-target processing, expansion of the antenna beam scanning range, miniaturization of the entire antenna connected to a signal processing system using digital processing, and so on.

[Brief description of drawings]

1 is a block diagram showing an antenna device according to an embodiment of the present invention, FIG. 2 is a block diagram of elements of the antenna device according to the present invention, FIG. 3 is a block diagram showing a conventional antenna device, and FIG. It is a block diagram of the element of the conventional antenna device. (1) is a conformal array antenna, (2) is a structural substrate, (3 ₁ ) to (3n) are elements, (4 ₁ ) to (4n) are signal lines, (5) is a microwave beam forming circuit, (6 ₁ ) ~ (6
n) the element antenna, (7) digital beam forming circuit, (8 ₁₎ ~ (8m) the output terminal (9) is monopulse pattern forming circuit (10 ₁₎ ~ (10k) is monopulse pattern output terminal, (11 ₁ ) to (11n) are low-noise amplifiers, (1
2 ₁₎ ~ (12n) is an analog digital converter. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] 1. A conformal array antenna having a structural substrate of a given shape such as the surface of an aircraft or the surface of a ship and a large number of elements arranged along the structural substrate. An analog-digital converter that converts the output of the noise amplifier and the low-noise amplifier directly or into an IF and then converts it into a digital signal, and the output of the analog-digital converter are combined to form m (m is 4 or more) beams. A digital beam forming circuit for
A digital signal corresponding to the m beams that are beam-combined by the digital beam forming circuit is input, and the sum and difference of the respective two beam-combined signals are calculated to form a monopulse pattern. An antenna device, wherein a monopulse pattern forming circuit is added.